330 yds. 440 yds. 880 yds. 2000 yds. Inches. Inches. Inches. Inches. Sand and earth 36 33 20 14 4 Steel and iron plate 0.31 to 0.38 0.28 0.24 Brick masonry 4½ Ice 63 Special steel-coated bullets, cal. 0.26 and 0.30: Pine wood 55 Oak wood, seasoned 16 to 24 Beech wood 23 to 30 Sand 14 Special steel-coated bullets, cal. 0.236, vel. 2600 f. s. Pine wood 62 French authorities give a muzzle penetration of 12 mm. = 0´´.473 in iron plates for the Lebel bullet. No published experiments confirm this. But few experiments seem to have been made to determine the penetration of the projectile of field and siege guns into earth, and the published data are very meagre and unsatisfactory. The German Engineer’s Handbook (Pionier Taschenbuch, 1892) prescribes the following thicknesses of parapets for cover against small-arm and cannon fire, viz.: ----------------------------+------------+------------+------------+------------ | |Shrapnel and| | Material. | Small Arm. | Splinters. |Field-guns. |Siege-guns. ----------------------------+------------+------------+------------+------------ Earth, sandy | 30" | 20" to 40" | 16½' | 23' Turf and marshy earth | 60" | | | Wood | 34" to 40" | | | Brick masonry | 15" | | | Brick masonry, single shot | | | 3' 4" | Two steel plates each 0.32" | 0.64" | | | Packed snow | 6' | | 26' | Sheaves of grain | 16½' | | | ----------------------------+------------+------------+------------+------------ English authorities report craters of 21 feet length and 8 feet depth blown out from an earth parapet by a single 200-lb. 8-in. howitzer shell. They also state that the projectile of the pneumatic dynamite gun has penetrated 40 feet of earth. Owing to the rapid development of ordnance the current scientific and military periodicals are in general the only source from which the latest results in penetration, etc., can be obtained. CONTENTS. ATTACK OF FORTIFIED PLACES. PAGE INTRODUCTION. v CHAPTER I. THE ATTACK WITHOUT THE USE OF REGULAR APPROACHES. ARTICLE 1. Blockade, 1 2. Surprise, 2 3. Defence against Surprise, 4